Internal-combustion engine piston



Jul 23,1946. L, B, BOYD 2,404,348

' INTERNAL-COMBUSTION ENGINE PISTON Filed Dec. so, 1943 .INVENTOR. I

fatented July 23,1946 I Applicamn December 1943,-seria1 No.1516t134?Claims, (Cl. 123 193 I Mypresent invention I in pistons, andparticularly to pistons for internal combustion, engines having acylinder block structure and a cylinder cover; and the objects of;improvement are: first, to provide an internal .combustion engine pistonthat will cause-improved combustion of the fuel .charge in fuel spaces.of the engine; second, to provide an internal combustion engine pistonhaving a thin layer of substantially pure copper forming a heatradiant,extending-throughout its head for refleeting heat of combustionback into ,thecombustion; chamber; third, to provide aninternalcombustion engine, piston. having. a, ,member I of copper extendingthroughout its head portion thatdoes-rnotg act ,as a-heat transfervmember;

. fourth, to provide an internal combustion. engine piston havinglessheat transfer to the wall of the cylinder in which the pistonreciprocatesthan veither pistons composed of non-ferrous metal or suchother piston having copper or other nonie'rrous metal at their heads;fifth, to provide an internalicom 'bi stion engine piston that canoperate on its reciprocative excursions with less main substantiallyfree from' carbon accumulation under its deckan'd'onthe .t'op'of thepiston;

' 'seventh, to provide 'an' internal combustion engine piston ofwhichthe pressure sealing rings 'will not become carbon bound eighth, toprovide an internal combustion engine piston whereby the horse poweroutput of the engine will be I greaterthan'th'at of internal combustionengines o'fqthfe same horse power rating and using the same quantity andquality fuel ninth, to provide an internal' combustion e'nginefpistonthat will "causea minimum of fuel consumption for a given horsepown'devempe'd by the engine; tenthfto provide: an [internal combustionengine piston that will cause a minimum consumption of lubri- I eatingoil; eleventh, toprovide aninternal' combustion enginepiston that willbe more efficient thanl such pistonsat present employed.

I attain these'named objects'andsuch other objects as'appe'ar from aperusalof the following description and the structure illustrated in theaccompanying drawing, in which:

ternal combustion engine cylinder block having ela est fim ov m ,thecrank pm of the engines crankshaft, and

' 2' Figurez is an elevation view of my pistonln part section. I 3 IFigure 3 is an enlarged cross-sectional view of a portion of an internalcombustion engine piston illustrating the application of copper or othermetals by other than my preferred method. I

Throughout the three views of the drawing, similar numerals refer tosimilar parts and portionsof my piston, as mounted 'in an internalcombustion engine, and referring to the drawing: Numeral I refers to mypresent internal combustion engine piston, comprising a skirt portion Zwith inwardly extending wrist pin bosses 3, each havin a bore 4 forrecei'ving'the wrist pin 5, 'to which is swingably connectedrod 6connected to whereby the crank shaftjis turned by the piston on itspower excursion and the piston is moved longitudinallyby power stored inthe crank shaft and; associated members I, on its compression excursion;a

. The skirt portion z ia'sjriar itslower endt annul ar ring slot I,having loosely mounted ther'ein outwardly springable 'oil film"regulating ring 8, and near its upperenda thickened portion I9 having aplurality of annular slots l0, each hav ing. therein an outwardlyspringable pressure sealing ring lll and outwardly'exte nding annularfiange of slightly lessdiameter than the skirt portion and the landsseparating .thefpressure sealing ring slotsQf I At the topof thethickened portion 9 and forming a portion of the outwardly extendingannular, flange H is the piston head or deck' l2, having secured to itsside nearest to the combustion of thefuel charge a thin ferrous. ,metalplate l2 having a higher resistance to heat transfer than the metal ofthe said deck l2, secured to the deck I I2 preferably by brazing with ahigh temperature melting point solder, and has at its side opposite theside from the said head deck a smooth heat reflecting. layer l3 havinghigh heat reflecting characteristics such as copper.' Both the plate 12-and heat reflecting layer l3 are shown extending throughout the topsurface of the head deck I2 and with the heat reflecting layer extending'beyond the periphery of the annular flange I I. with a thinbeveled edgel3 lightly ena cylinder cover extending over its top and a piston iscaused to reciprocate.

gaging the wall of the cylinder bore in which the 5Q Figure 1 is avertical sectional view of an in- I Numeral [4 refers to a cylinderblock or frame of an internal combustion engine provided with a cylindersleeve 15 having outwardly extending annular flange [6 at its topresting on annular ledge ll of the cylinder block or frame, havingcylinder cover [8 secured to its top surface with a suitable highpressure heat resisting packing interposed between the cylinder blockand cover.

Numeral l9 refers to the combustion chamber 7 of the engine which shouldbe of suitable form for the engine in which the piston is to be used, asdifferent designs of engine require differently formed combustionchambers. Numeral 20- refers to the fuelintake valve operated by thevalve stem 2i for admitting gaseous fuel to the combustion chamber I9from fuel intake passage 22; numeral 23 designates the ignition sparkplug V and 24 the chamber containing the cooling fluid I of the cylinderblock or frame. v

Referring to Figure 3 therein is shown a meth- 0d of securing copperdirectly to the top of the pistons head by the metal being melted intoa, recess extending over the deck of the piston, and into annulargrooves 26 machined into the said of the present application, the Viewmerely shows ,a method whereby copper or other metal having a lowermelting temperature than ferrous metal can be app-lied to the head of apiston.

Applicant isaware thatprior to his present invention copper ofconsiderable thicknesshas been attached to the head .portion of internalcombustion engine pistons for the express purpose of uniformlytransferring heat caused by combustion in the combustion spaces abovethe piston :30 I I fer tothe piston skirt and cylinder wall with itsdissipation by a cooling medium.

to the head of the piston to be dissipated by air circulated within thepiston against the under side of the head, and also conveyed by the headto the surrounding skirt -portion and therefrom to a p the cylinderwall, which" of most internal combustion' engines'is surrounded by acooling fluid circulated through cooling fluid chambers and air 'cooledradiators, all making it necessary to provide suffi'cient metalthroughoutthe piston 7 structure to carry the heat of' combustion tothe" 40 ciableamount; also, the copperlayer I3 or other satisfactoryn'onferrous metal that might be employed having similar heatcharacteristics, is being secured to the felTOlls metal plate l2"having-" a higher resistance toheat transfer than the metal of said deck12 and which in turn is'secured to the head deck of the pistons, forms aresistance to coin'bustion heat transfer from the copper to the headdeck of the piston and to the oil and atmosphere circulating within thepiston; all of which contribute to producing higherroperatingeiiicien'cy'of the enginein whole, as the thin layer of copper beingsmooth at its combustion exposed surface acts as a radiant to reflect ordeflect and throwback iiito'thecombustion spaces-of the engine heatto'cause'uniform heating of the sucneeding gaseous fuelcharges'draw'ninto the combustion spaces of the engin'e and thereby morenearly perfect and uniform; combustion of the 2,404,348 r j ii? T1.

fuel is obtained; further, the thinness of the copper metal layer l3approximately one sixty-fourth prevents accumulation of carbon withinthe pis- "ton'g as where the lubricating oil is splashed against theunder side of the head deck of a piston when heated, as it is ininternal combustion engines having assisted heat transfer by a heattransfer means, form, a deposit of carbon throughoutmost of the interiorof the piston,

' and also in the pressure sealing ring grooves, thereby preventing freeaction of the rings. This formation of carbon in the piston contributesto excessive oil consumption and the prevention of pressure sealing ringfree action contributes to 7 high fuel consumption. 1 V

"In-my internal combustion engine piston there 'is the layer ofsubstantially pure copper metal of approximately one-sixty-fourth inchthickness, -which acts as a radiant to divert'or throw back intothecombustion spaces of the engine, heat caused by 'combustion, and to themeans of at taching the copper to the ferrous metal plate, and theferrous metal .plate to the head deck, together with the ferrous metalplate, dampens heat trans- Having described my present invention claim:I 1.-"An internal for reflecting back into the'combustion spaces heatcaused by'combu'stion of, fuel in said combustion'spaces.

:2. In anjinternalbombustion engine piston having a skirt with'a headdeck associated therewith,1machined 'atfits top side exterior of thepiston, a ferrous metal plate jo ned to the ma-' ,chined side of thehead deck of the piston, and 1 having, at its opposite side from thehead deck a heat radiant'surface forirefiecting heat of combustion backinto the combustion spaces of the engine.

"3. In,an internal combustion engine. piston having askirt and a headdeck the head deck having witha machined side external of the pistongi'asteel plate having a copper metal "layer notexceeding one sixty-fourthinch thick joined to .one'of its'flat sides, with the steel plate fusedto the mac'hined'side of vthe head deck. 4. Inan internal combustionengine piston, the

combination of ahollow, piston'body having a head deckclosing' one ofits ends with a ferrous metal plate having a fused joinder with"the headdecjk-exteriorofthe piston,'and,hav,ing a I nonferrou'slmetal layerintegral with the ferrous nietaiplate at the opposite side thereof,"from the headdeck.-, i" f t 1 LANDONBL'BOYD.

relating'to; internal combustion enginepistons, I

combustion engine piston havinga' copper metal layer forming a heatreflector head, ,and fastened thereon by a ferrous metal plate secured tthe head deck of thepiston-and having a-lesser heat conduction factor'th'anjthe heat 'conduction'factor'of thecopper

